The objective of the proposed research is to advance understanding of the role of environmental and psychosocial influences on the pediatric precursors of adult atherosclerosis. Cohorts of genetically similar infant and juvenile nonhuman primates (Erythrocebus patas) are used as models of the human pediatric age group and are monitored from weaning until adolescence. In order to test the effect of environmental and psychosocial influences on this age group, a portion of the animals are maintained in an environment reasonably ideal for physiological, behavioral, and sociological development while another portion will be in an environment specifically designed to impede normal development. Both groups are subjected to a diet moderately rich in cholesterol and salt, designed to mimic that consumed by young North Americans. Longitudinal measurements of behavior and physical activity/exercise will be made together with longitudinal measurements of blood pressure, plasma lipid concentrations, endocrine function, and growth and development to determine whether the relationships among these factors are affected by contrasting living conditions. At the end of the experiment, necropsies will be performed on the experimental animals to determine the extent and severity of atherosclerosis. Variability in this factor will then be examined for any relationships to living conditions and the above mentioned clinical and behavioral factors.